salsa20.h 2.79 KB
Newer Older
1 2 3 4 5 6 7 8 9
/* salsa20.h
 *
 * The Salsa20 stream cipher.
 */

/* nettle, low-level cryptographics library
 *
 * Copyright (C) 2012 Simon Josefsson
 * Copyright (C) 2001 Niels Möller
Niels Möller's avatar
Niels Möller committed
10
 *
11 12 13 14
 * The nettle library is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or (at your
 * option) any later version.
Niels Möller's avatar
Niels Möller committed
15
 *
16 17 18 19
 * The nettle library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
 * License for more details.
Niels Möller's avatar
Niels Möller committed
20
 *
21 22
 * You should have received a copy of the GNU Lesser General Public License
 * along with the nettle library; see the file COPYING.LIB.  If not, write to
23 24
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA 02111-1301, USA.
25
 */
Niels Möller's avatar
Niels Möller committed
26

27 28 29 30 31 32 33 34 35 36 37
#ifndef NETTLE_SALSA20_H_INCLUDED
#define NETTLE_SALSA20_H_INCLUDED

#include "nettle-types.h"

#ifdef __cplusplus
extern "C" {
#endif

/* Name mangling */
#define salsa20_set_key nettle_salsa20_set_key
38 39 40
#define salsa20_128_set_key nettle_salsa20_128_set_key
#define salsa20_256_set_key nettle_salsa20_256_set_key
#define salsa20_set_nonce nettle_salsa20_set_nonce
41
#define salsa20_crypt nettle_salsa20_crypt
42
#define _salsa20_core _nettle_salsa20_core
43

44 45
#define salsa20r12_crypt nettle_salsa20r12_crypt

46 47 48 49 50 51 52
/* Alias for backwards compatibility */
#define salsa20_set_iv nettle_salsa20_set_nonce

/* In octets.*/
#define SALSA20_128_KEY_SIZE 16
#define SALSA20_256_KEY_SIZE 32
#define SALSA20_BLOCK_SIZE 64
53 54
#define SALSA20_NONCE_SIZE 8
#define SALSA20_IV_SIZE SALSA20_NONCE_SIZE
55 56

/* Aliases */
57 58 59 60
#define SALSA20_MIN_KEY_SIZE 16
#define SALSA20_MAX_KEY_SIZE 32
#define SALSA20_KEY_SIZE 32

Niels Möller's avatar
Niels Möller committed
61 62
#define _SALSA20_INPUT_LENGTH 16

63 64
struct salsa20_ctx
{
Niels Möller's avatar
Niels Möller committed
65 66 67 68 69 70 71 72 73 74
  /* Indices 1-4 and 11-14 holds the key (two identical copies for the
     shorter key size), indices 0, 5, 10, 15 are constant, indices 6, 7
     are the IV, and indices 8, 9 are the block counter:

     C K K K
     K C I I
     B B C K
     K K K C
  */
  uint32_t input[_SALSA20_INPUT_LENGTH];
75 76
};

77 78 79 80 81
void
salsa20_128_set_key(struct salsa20_ctx *ctx, const uint8_t *key);
void
salsa20_256_set_key(struct salsa20_ctx *ctx, const uint8_t *key);

82 83
void
salsa20_set_key(struct salsa20_ctx *ctx,
84
		size_t length, const uint8_t *key);
85 86

void
87 88
salsa20_set_nonce(struct salsa20_ctx *ctx, const uint8_t *iv);
  
89 90
void
salsa20_crypt(struct salsa20_ctx *ctx,
91
	      size_t length, uint8_t *dst,
92 93
	      const uint8_t *src);

94 95
void
salsa20r12_crypt(struct salsa20_ctx *ctx,
96
		 size_t length, uint8_t *dst,
Niels Möller's avatar
Niels Möller committed
97
		 const uint8_t *src);
98

99 100 101
void
_salsa20_core(uint32_t *dst, const uint32_t *src, unsigned rounds);

102 103 104 105 106
#ifdef __cplusplus
}
#endif

#endif /* NETTLE_SALSA20_H_INCLUDED */